Hardness testing in water softeners



' E. PICK 2,122,824

HARDNESS TESTING IN WATER SOFTENERS July 5, 1938.

Filed NOV. 22, 1955 4 Sheets-Sheet 1 r l t E771 P icfi, 7 11 .2

July 5, 1938. E. PICK HARDNESS TESTING IN WATER SOFTENERS 4 Sheets-Sheet 3 Filed Nov. 22, 1935 HH'RDNESS TESTER 4:2: WKSTB 17 m P/ZLCK,

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July 5, 1938. l E PIC 2,122,824

HARDNESS TESTING IN WATER SOFTENERS Filed Nov. 22, 1935 4 $heetsSheet 4 577,6, P ZLQIC,

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reams JulyS, loss) 2,122,824 naammss res-mm IN wanna somima's Eric Pick, New York, N. Y., 'assignor to The Permntit Company, New York, N. Y., a corporation of Delaware Application November 22, 1935, Serial No. 51,151

9 Claims.

This invention relates to hardness testing in water softeners; and it comprises apparatus for producing an electrical indication dependent upon hardness in water, comprising a source of light, a photoelectric cell opposed thereto, a trough therebetween, the sides of which lie below the source and the cell so as not to obstruct illumination, on the cell, means for mixing water with soap solution in predetermined proportions,

1 means for agitating such mixture to form a lather of large volume when the water is soft and curds of less volume when the water is hard, means for passing the mixture into the trough so as to cause any lather formed to flow above the 1 sides of the trough and to'obstruct the light.

. from the source; and an electrical instrument of, the galvanometer or relay type in circuit with the photoelectric cell and adapted to respond to changes in illumination thereon and thus to re- 20 spend to hardness changes; and to signal the occurrence of hardness in water being softened or to start regeneration of a motorized softener in automatic response to the hardness; and it further comprises a. method of testing water for 5 hardness which comprises mixing water and soap solution with excess air and passing-the aerated mixture in such relation to a beam of light as to diffuse the beam when soft-water lather is present and not to diffuse the beam when lather is an absent, and photometering the beam; all as more fully hereinafter set forth and as claimed.

In conventional zeolite water softening practice, raw water of varying hardness is passed through a bed of base exchange materials (zeo- 35 lites) containing exchangeable sodium whereby calcium (or magnesium) hardness is exchanged for sodium and an eilluent water of zero hardness is obtained. In the course of time, the zeolites lose all, or most, of their exchangeablesothis being replaced by calcium from the water. stopped and the zeolites are regenerated by passing brine (a solution of NaCl) through the bed.

The zeolites take up sodium from the brine and form calcium chl'orid solution which is passed to waste. .When the softening is by downward flow, it is usual, prior to the brining operation to subject the zeolite bed to a backwashing operation to free it of deposited foreign matter.

50 After the brining operation, residual brine is rinsed from the bed with water.

There has recently been developed improved apparatus for automatically regulating the serial operations of softening, backwashing, brining 55 and rinsing. Usually, the termination oi? the The water softening operation is then '(ol. zs-zso) softening stage is set, not directly according to appearance of hardness in the efliuent water or imminent appearance thereof, but, instead, is determined according to gallonage passed;-.by a volumetric water meter. There is first found by experiment the quantity of water of a givenhardness which can be softened by the bed, and theapparatus is set to stop the water softening operation when this quantity has been passed. The meter control setting can be adjusted manually when the water changes in hardness. This type of apparatus is very satisfactory as regards dependability and freedom from the necessity of supervision. However, it works without waste only when the meter control is accurately adjusted to theamount of, hardness in the raw water and when the hardness does not vary.

The hardness of many supplies of raw water is by no means constant. For example, municipalwater supply systems are often fed from a large lake or open reservoir. A heavy rain or snow fall adjacent the lake may be sufficient to reduce the hardness of the water considerably within a period of 24 hours. Many water supply systems are subject to variation of hardness periodically throughout the year. Ordinarily, hardness is greater in the dry season and less in the wet season. I

Attempts, more or less successful, have been made to test for small amounts of hardness in water and to automatically control the operation of water softening according to hardness appearing in the softened water. Use of the difference in conductivity between hard water and v soft water is known. The most reliable indication of degree of hardness is the well known soap test. A sample of the water is shaken up with gradually increased dosages 'of a soap solution of known strength. Any hardness present in the water sample reacts immediately with the soap to form insoluble curds; calcium or, magnesium soaps. A small quantity of soapsolution added to the sampleafter all its hardness has combined with the soap will then form a lather upon agitation or shaking, which indicates the end point of the test. The hardness of the water sample is then computed from the quantity of soap. solution required to form a lather.

There has been developed an automatic indicator and controller wherein a mixture of the water under test, and soap solution, is passed through a glass cell interposed between a source of light and a photosensitive device, The more the turbidity or curdiness in the water, the less lightgets to the photosensitive device. This aris only a slight difference between the ourdiness or transparency of soft water and that of water containing a small amount of hardness. Nevertheless, the arrangement works satisfactorily.

One object achieved in the present invention is the provision of apparatus for giving an electrical indication .of a predetermined degree of with cover removed;

hardness in water, with the aid of soap solution mixed therewith, the apparatus being so constructed as to eliminate the necessity of providing glass windows between which the water-soap mixture must pass.

Another object is to provide a hardness indicator in which water andsoap solution are agitated to form a mixture which is passed into a trough between a source of light and a photoelectric cell, the disposition of the parts being such that; when the water is soft and a bulky floating lather is formed, the lather projects above the trough and obstructs the light while,

when the mixture is of a curdy nature by reason of hardness in the water, the lather flows along without rising above the sides of the trough and does not obstruct the light. This eliminates the necessity for cell glasses.

Another object is to provide a hardness tester which responds positively 'to the appearance of a predetermined-degree of hardness in the water sample. The change from a small or zero light incidence for soft water to full light incidence for water of a predetermined minimum degree of hardness produces a large and easily measurable change in the output of the photoelectric cell.

This makes the apparatus positive in-its action and eliminates any loss in accuracy due to changes in photoelectric cell characteristics, etc.

Another object is the provision of apparatus for accurately and uniformly controlling operations of an automatic water softener according to hardness of waterat some part in the system, the app ratus not being subject to error due to deposition of matter from the water.

These objects are achieved according to the invention. 'I'he inventio'n' comprises a source of light, a photoelectric cell opposed thereto, a trough therebetween, the sides of which are so shaped as to be depressed below the beam of light, a dam in the trough, an agitating box provided with a whipper and screen delivering to the trough, and means for supplying the agitator box with samples of water together with soap solution' in predetermined proportions. Ina modification, compressed air is used for agitation.

In the accompanying drawings are shown 'examples of two specific embodiments of the invention, including its application to control of a water softener. In the drawings Fig. 1 is a plan view of the indicating apparatus Fig. 2 is an end view. in elevation corresponding toFig.l;' i

Fig. 3 is a diagrammatic plan sectional view taken along line 3-.-3 of Fig. 4 to illustrate the trough and optical system;

Fig. 4,is an elevational' view partly in section taken along line 4-4 of Fig. 3 to show the agitating device and trough;

rangement is of necessity delicate because there Fig. 6 is a view in sectional vertical elevation taken along line 6-6 of Fig. 5;

Fig. 7 is a section taken along line 'l| of Fig. 5;

Fig. 8 is a plan sectional view taken along line 8-8 of Fig. 7 to show the valve;

Figs. 9 and 10 are'views in vertical section and plan, respectively, of the container for soap and water, Fig; 9 being a section on the line 9-9 of Fig. 10;

Fig. 11 is a diagrammatic view partly in vertical section and partly in elevation, of a modification using compressed air for agitation; and

Fig. 12 is a diagrammatic view showing the application of the invention to a control system for an automatic water softener.

In the showings, in which like reference characters indicate like parts throughout, the apparatus is shown as comprising a trough 20 having sides 2| and two U-shaped slots 22, an end dam 23 and a weir 24 (Figs. 1 to 4). The trough is adapted to contain a flowing soap-water mixture 25 which runs over weir 24 to waste receptacle 26 communicating with a waste pipe 21. Receptacle 26 surrounds the end and sides of the trough, as shown (Figs. 1 and 3). The trough is supplied with soap-water mixture from an agitating box 3|! in direct communication with the trough through a screen 3| and having an agitating device comprising a blade 32 with a number of perforations 33, mounted on a shaft 35 driven by a verticalmotor 36 at high speed. The box 30 is mounted on the base 85 of the apparatus. The

' box is supplied with a mixture of soap and water through a pipe 31. Onone side of the trough 20 is mounted a photoelectric cell 40 in a suitable casing 41 having an opening 42 surrounded by a light shield 43 to cutofi' extraneous light. The photoelectric cell can be of any suitable type. For example, alkali or alkali-metal cells, either of the vacuum'type or gas filled, these types being used with an amplifier; or photoelectrolytic cells or those of the dry copper oxid type, both of which can be used to operate sensitive instruments directly. At the present time, I regard as the most suitable cell for my purposes one of the dry copper oxid type. On the other side of the trough is positioned a source of light in the form of a small electric bulb 45 having a concentrated filament 46. The apparatus can be arranged so that light from the bulb falls directly on the photoelectric cell, but it is better to provide concentrating apparatus. Thus, a condensing lens 41 is mounted in front of the bulb so as tofocus the rays approximately in the center of the The lasting quality of the lather depends upon the hardness of the water. Softwater on 2131 I tationwith soap forms a relatively long lasting and bulky lather, while hard water merely forms a compact curd suspension from which the air bubbles escape immediately after agitation so 7 that the outflowing mixturehas substantially no greater volume than it had prior to agitation. The lather formed with soft water flows into the trough (28) through screen 3|, which allows when the water is'soft is indicated by the dotted line Si in Fig. 4. I

On the other hand, when the water is hard, the mixture whipped up by the agitator is a liquid curd suspension. It flows along the bottom of the trough as indicated in full lines in Fig. 4, below screen 3i, leaving the U-shaped slots 22 open. Any lather present in the trough is rapidly carried away by the hard water flowing through the trough. Only part of the hardness of this water having reacted with the soap supplied to the mixture, the remaining hardness reacts with the lather and transforms it to curds which are carried away by the outflowing mixture. Light falls unobstructedly on the photoelectric cell which develops a current. Electrical connectio'nis madeto the cell through wires 52 and 53. These wires are connected by wires to an indicator 55 of the galvanometer type, conveniently a milliammeter, having a scale 58 and the .legends "Soft" and fHard", as shown. A pair of binding posts 51 is provided connected by wires 58 in parallel with the meter, connection being made to wires 52 and 53 as at and I3. The binding posts are for optional connection to a relay and control system, described post.-

While I have found a motor driven agitator blade most satisfactory, invlieu of this agitating means compressed air, from a compressed air system available in many-plants or from a separate compressor, may ,be introduced into the bottom of box 38 for the purpose of agitating the mixture and producing a lather if the water is soft.

In a modification the source of light and the photoelectric cell may be so arranged relative to the mixture in the trough that the light rays from the source, are projected at an angle toward.

the surface of the liquid in the trough tobe reflected by the surface towardthe cell when the water is hard. Then, with soft water, the lather floating on the surface of the liquid diffuses the light and deflects it from the photoelectric cell and this reduces theefiective illumination on the photoelectric cell.

Turning now to the apparatus for supplying the agitator box with a predetermined mixture of soap and water, these means comprise a float box control for water and a reservoir for soap. These are combined in a duplex tank 88, shown in detail in Figs. 9 and 18. The tank has a dividing wall 8| defining a chamber 62 for soap solution, having a removable filling plug 83 vented as at I3 and anoutlet 84 in communication with soap pipe 85; and an upper open float compartment or chamber 88 for water to be tested. Tank 88 is supplied with water through an inlet 81 in communication with a sampling conduit 88.

Ordinarily, water flows into the tank by hydrostatic pressure, but auxiliary pump means can be provided-if required. A float valve control is provided having a float valve 88 operable by a float I8 and delivering into a pocket II formed by a dam I2. The .pocket has an outlet I5 in communication with a conduit I8 leading to the water pump, to be described. The pocket retains a small quantity of the latest or freshest sample of water. In order to shorten the time lag of the apparatus, an excess of water is taken from the system beyond the requirements of the sampling apparatus. This excess is allowed to flow off through waste pipe H in communication with the float compartment through outlet I8. A valve 18 in the waste pipe can be adjusted to control the rate of discharge. The float valve operates to maintain a constant water level in compartment 88.

Water and soap solution are supplied from tank 88 to box 38 in predetermined proportions with the aid of two proportioning pumps. These are illustrated in detail in Figs. 5 to 8. A motor 88 (Figs. 1 and 2) is provided having speed reducing mechanism 8i with power shaft 82, the

reduction being such as to cause the power shaft to rotate several times a minute; The motor can be of very small size; a small fraction of a horsepower. It is supplied with current through wires 28 connected to wires I9, as shown. Power shaft 82 drives a shaftextension 83, mounted in bearings 88 supported on the base 85 of the apparatus, a coupling 88 between the two shafts being provided. 4

A double eccentric 81 is mounted on shaft 83. The eccentric has two circular rims 88 and 88. Eccentric rim 88 is provided for operating the water pump. For operating the soap pump, there is provided an eccentric device adjustable as to stroke. This comprises a collar 95 pinned to the end of shaft 83 by pin 88 and having a screw 91 pivotally mounted in the collar 85, carrying a nut 88 having a projecting pin 99 serving as a crank arm. A connecting rod I88 connects pin 88 with the piston I8l of the soap pump through a pivoted joint and pin I82. The piston is housed in a cylinder 84. Eccentric rim 88 is provided with an eccentric-strap I83 fastened as at bolted joint I84 over the rim and having a connecting rod I85. The water pump comprises a cylinder I88 containing a plunger piston I81 having lugs I88, pivoted to the end of rod I85 by a pin I88. Cylinder packing is provided, comprising packing material I I8 and stufiing nut III. Upon rotation of shaft 83, the pistons of the two pumps are oscillated back and forth, in phase.

Below the two cylinders is positioned a valve box II2 having a base plate H3 and a side and top piece I I8 (Fig.7), the assemblage being bolted to the base 85 of the apparatusby a plurality of bolts II5, as shown. Water is delivered to the valve box through pipe I8 delivering into the valve box through a bore I28, a liquid tight connection being made by stufling nut I2I, with appropriate packing. Soap is delivered to the valve box through pipe 55 deliveringwthrough a bore I22 sealed by a similar stufling nut I23. Mixed liquid leaves the box through a bore I24 (Fig. 8) having the valve box. Fig. 8 shows'the valve position during the intake strokes of the pumps. In this position, the valve connects the soap solution pipe (85) with the soap pump cylinder (98) throu h port I22, channel I21 and port'l30. The valve also connects the water pipe (13) to the water pump cylinder (I05) through port I20, channel I28-and port I31. The outlet pipe 31 is shut oil. in this position; channel I23 does not connect port I24 with any other port. A pair of springs I35 hold the valve slide tightly against the under face of element H4. The valve slide can be of metal or, in some cases, of hard rubber or of hard rubber backed with metaL.

The valve operating linkage is shown in detail in Figs. 5 and 6. The linkage is operated from shaft 83 through eccentric rim 89. An'eccentric band I 36 encircling the eccentric rim is provided as shown, the band being connected to an arm I31. A sliding plate I38 is mounted on the base of the apparatus, longitudinal slots I39 being formed in the plate surrounding screws I40 which hold the plate to the base in a smooth sliding fit. Rod I31 is pivoted to the offset end of the plate by a, pin I H, as shown. Thus rotation of shaft 83 by themotor causes the plate to slide back and forth, in phase with the eccentrics.

Three stationary pedestals,,l45, I46, and I41 are fixed on the base of the apparatus. Pedestal I46 has pivoted thereto at I43 a'link I 49, the other end of which has a pin I50. Pin I50 is connected to a pair of lugs IS! on the slide valve through a connecting rod I52 and a pin I53. Link I49 also has a fixed pin I54 near the upper end thereof. Link I43 also has a pin I30 to which are attached two springs ISI and IE2. The other ends of the springs are attached to plate I33 as shown. At

the upper end of pedestal I 45 is pivotally mounted,

as at I63, a latch I64 having a detent portion I65. A similar latch I33 is pivotaliy mounted as at I61 at the upper end of pedestal I41. This latch has a detent portion. I 68. The lower portions of the two latches are provided with detent hooks I69 and I10, adapted to grip pin I54 at certain positions. The eccentrics are covered. by a housing 28, as shown. 1

The valve operating mechanism can best be understoodby considering the operation of the device. Assuming the motor 30 to be rotating, Figs. 5 to 8 show the apparatus just after the end of the discharge and at the beginning of the intake, of both piston strokes. A mixture of water and soap has just been forced by the pistons through pipe 31 into the agitating box 30 and the valve slide has now moved to cut oif this connection and to make connections between the sources of water and soap solution and the water cylinder and soap cylinder, respectively, as described in connection with Fig. 8. As the shaft 83 rotates clockwise the pistons move to the right, sucking soap solution and water into the two pump cylinders through the connections as described in connection with Fig. 8.

As the pistons near the outer end of the suction stroke, collar I". carried on connecting rod I05 strikes the detent portion I65'of latch I64 and starts to rotate the latch about the pin I63. At

this time connecting arm I31 has moved to the extreme right thus sliding plate I38 to the extreme right and placing spring I32 under tension and relieving spring I3I of tension. At outer dead center collar 111 has moved detent portion I35 so as to release hook I33 from pin I54. The

tension of spring I63 causes link I43 to snap about pivot I43 to the right, until pin I54 engages hook I10 in latch I86. ,The link in changing position moves connecting rod ii! to the right and thus shifts the .valve slide to the extreme right. "This positions the valve-slide for discharge of soap two cylinders are now filled with soap 'solution' and water. As the shaft rotates beyond outer dead center, the pistons are forced inward, thereby forcing soap and water into pipe 31. Latch I64, after it has released pin I54, isbrought backto normal position by the action of spring I15.

As the pistons approach the end of the discharge stroke, collar.l18 on connecting rod I05 engages the detent end I 68 of latch I66 rotating the latch about pivot I31. At this time connecting arm I31 has moved plate I38 to the left, placing spring IBI under tension and releasing tension from springIBZ. At inner dead center, the end of the discharge stroke, collar l'IB has rotated latch I66 suiiioiently to release pin I54 from hook I 13. Under the tension of spring IGI link I43 rotates swiftly until pin I 54 engages hook I69 in latch I64. The shift in position of link I49 moves the slide valve to the extreme left, positioning the valve for introduction of soap and water to the cylinders. The position shown in Figs. 5 to 8 is thus resumed. Latch "it is returned to normal position by spring I16 after it has released pin I54.

While an aqueous soap solution canbe dead, I find it is better to use a concentrated alcoholic solution of soap. Any common soda or potash soap is suitable. The soap chamber 82 in tank -30 is sealed by cap 63 to prevent evaporation of the alcohol. The adjustment of screw 31, (Fig. 5) determines the relative proportions of soap solution and water which are fed to the agitator box.

It is a simple matter to adjust this screw so as to make the apparatus respond ;to any degree of hardness desired.

In Fig. 11 I have shown a modification of the device which has advantages in certain relations. Compressed air is used for agitating in lieu of a mechanical whipper. As shown, there is provided a box 300 of irregular shape, having a well- 3IlI and a lateral extension 302. The top of the box is open, as shown; A depressed weir 304 is provided, and below it a waste box 335 delivering to waste conduit 21 as shown. The box is adapted to contain a body of soap-water mixture 3%, the upper level of which in the case of hard water is indicated at 301. A mixture of soap and water is delivered to the box through pipe 31. Pipe 31 leads from proportionating apparatus such as water is soft, there is formed a lather the surface of which is indicated as at 3I3. If the water is hard the surface remains substantially as shown at 301. The soap-water mixture flows over weir 304 and to waste as indicated at 3I3.

The compressed air agitating box described is particularly useful with a modification of the invention in which the optical system is a reflection system rather than a transmission system. As shown, light box 43 is mounted so as to direct a beam downward at an angle upon the surface of the soap-water mixture. The photoelectric cell araasas through pipe 81 substantially as described in connection vwith previous figures. Compressed air is fed in continuously and agitates the mixture in well 25!. While the sampled water is soft, the compressed air causes formation of a lather, as indicated (M3) The lather rises above dam 2".

Light is no longer reflected into the photoelectric cell, but is dissipated as indicated by broken lines U8. The surface -of the lather diffusesthe light and moreover the change in level keeps direct reflected rays from getting to the cell. As a result, the cellregisters a low or zero current.

- When the water becomes hard, the agitation does not result in production of a lather and the surface 881 remains level and clear. The major portion of the beam from thelamp is directed into the photoelectric cell, which produces a current.

The photoelectric cell isconnected to the meter and relay switch through wires 52, 58, exactly as described ante in connection with the other figures.

I In this modification, as in that of Figs. 1 to- 10, the lather when present diffuses the. light beam from the source and the photoelectric cell is arranged to photometer the beam and thus to indicate presence of lather which corresponds to softness. When, however, hardness occurs in the sampled water, the lather disappears and the resulting increased photoelectric cell current resisters hardness by the galvanometer.

The apparatus is useful as a simple indicator, the ammeter 55 showing whether the water at a given point in the system is soft or hard. The apparatus is also useful for controlling an automatic softener according to hardness; that is, to stop the softening operation and start regeneration when hardness appears at some point in the system. One example of a specific embodiment of the invention as applied to water soften er control is diagrammed in Fig. 12. e

In Fig. '12 the invention is shown applied to a softener having an automatically actuated and timed multiport valve. The softener proper includes a container 258 for zeolites, having lower connection 2" and upper connection 282.- Flows to and from the softener are controlled by a single multiport rotary valve 258 having connections as at 284 and 205 to conduits 282 and 2M, and an inlet 286 for raw water and outlet 201 for softened water.- The valve has other connections (not shown) for brine and waste. The valve has a stem or shaft 288, adapted to be actuated through reducing gearing 206 by an electric mo;

tor 2. The motor current, supplied through wires 2 M, is controlled by a normally open switch 2!! adapted to be closed by ener'gization of a solenoid 2l6; Upon actuation of the motor the valve is caused to rotate intermittently to fixed angular positions corresponding to the several flows of the regeneration cycle and ofsoftening.

The valve shaft operates a circuit breaker arm 2" mounted on acontact hub 2" fixed to shaft 288. Four arcuate contact elements 2", 228,

supplied 22 l and 222 are mounted becontacted by arm 2" during its rotation. Abrush 222 makes sliding contact with hub 2l8. 'Ihefunction of the circuit breaker is to causethe valveto assume predetermined angular positions; a

The valve operation is timed by a -timer comprising an insulating drum 225 carrying contact segments and driven by a constant speed motor 225. The drum is shown developed for the sake of clarity; that is, the cylindrical surface is shown in Fig. 12 as being laid out flat. Actually edge E in the diagramcoincides withedge F. The drum has four contact members;221, 228, 225, and 2". Eight fixed brushes, 236,236, 221, 228, 228, 248', 2, and 242 engage the surface of the drum as indicated. I? I i A brine tank 255 of conventional form is provided, having a float switch 25l adapted to break contact when the brine tank is full and to make contact when the brine level falls to -a predetermined p'oint. Conduit connections from the brine tank to the softener are omitted for the sake ofclarity. a

A solenoid switch 258 is provided having a coil 255, a contact arm 255 and four contact points 258, 251, 258, and 258. 1 i The hardness tester is adapted tooperate this solenoid switch through wires 268 and'26l connected to binding posts 51 of the hardness tester. The hardness tester takes water'samples through sampling pipe 68, the inlet of which is usually positioned adjacent the bottom of the softener as at from the figure 262, being shown at a level slightly above that I of the outlet connection 281.

The electrical connections for-the various elements described are as follows. Control current, which is ordinarily single phase alternating current, is supplied through two wires 26! and 265.

A branch 266 leads from wire 25! to one "side of solenoid switch 2. The other side of the solenoid is connected through a wire 261 with contact point 231. It is also connected through wire 258 with the brine tank floatswitch. 25f. Wire" 25 leads directly to contact points 255 and 258 of relay switch 252, as shown, Contact points 251 and 258 of the relay switch are respectively connected directly through wires 258 Jand-210to contact points 225 and 286 of'timing drum 225.

Wire 265 leads to one terminal'of timing motor 226. The other terminal of the timing motor is connected through a wire 215 withacontact point 215 engaging contact member. 2210f the timing drum. Wire 285 has a branch 211 connected to circuit breaker brush 222. Drum contactjpoints 228, 282, and 288, respectively, are connected to' circuit breaker segments 2l5, 22 6,'j and 222 through wires 288, 2", and 282." Segment 22! is connected through a wire 288 with float switch 25l. Drum contact points 288and2ll are connected through a wire 286 with wire 261 as shown.

Considering the operation of this; system, when water flowing through the samplingpipe is soft, solenoid 254 remains unenergizedintheposition shown, making contact between points258 and 258. The valve shaft 258 is shown in softening position, and it is assumed that thesystem has just. returned to this softening stage and that 1 softened water is flowing from the softener.

Switch 2| 5 is open, as shown; the valve operating motor is not running. The timing circuit is completed through wire 264, points 25 8 v andy25fl,

wire 218, point 285, segment 221, polnt;216,-wire 215, timing motor 225 and wire 265. Thus the motor is caused to turn the drum. Drum 225 turnsuntil thecircuitisbrokenbysegment 221 point motor226 stops. In the meantime, contact 266 and 261. Hence drum 226 remains stationary. The softening operationcontinues until hard waterappears inthe water sample. The drum speed and contact positions are so adjusted that become steady.

the timing motor comes to a stop as described some time prior to appearance of hardness. Thus the hardness tester is what actually initiates regeneration. =Upon appearance of hardness, relay switch 2661s energized by the hardness tester, breaking connection between points 266 and 269 and making'connection between points 266 and 251. During thetransition period while the water changes irom'soft to hard, there occurs alternate rising and falling of the lather, which causes varying illumination on the photoelectric cell and thereby fluctuations in the cell output. This causes the relay switch to flutter. This condition lasts only a short time but it is desirable to delay initiation of regeneration until conditions Each time contact is made throughpoints 266 and 261 during the flutterings, the timing circuit is completed through point 265, segment 221, point 216, wire 216 and the motor. Thus the motor is caused to operate, intermittently advancing the drum.

Regeneration isinitiated when contacts 261 and 266 come in contact with edge A of segment 226 and a control circuit is thereby completed through wire 266, wire 211, brush 226, hub 2",

arm 2l1,arcuate segment 2 I 6, wire 266, point 266,

segment 226, point 261, wire 261, solenoid switch 2l6, Lwire 266 and wire'264. Thus switch 2l6 closes and turns on motor 2). The motor rotates the valve until arm 2" leaves strip 2|:I, thus breaking the circuit, and engages segment 220. This angular position corresponds to back- .washing position of the valve. The valve motor stops. "The timing motor 226 however remains energized and continues turning the drum. Back- *washingicontinues until segment 2 on the timing-drum closes points 24! and 242.

The duration of thebackwashing step can be varied by adjusting the circumferential position of segment 26I. A control circuit is thus completed through wire 266, wire 211, arm 2", segment 226, wire 26!, points 2 and 242, wire 264, wire 261, solenoid switch 2l6,.wire 266 and wire 264.

The motor 12M now turns the valve shaft until arm 2" leaves segment 220, engaging segment leaves strip .221 for strip 222, at an angular valve position corresponding to rinsing. Rinse water passes into the softener to displace brine from the zeolites prior to a new softening stage.

, In the meantime, timing motor 226 has stopped, after rotating drum 226 to such position that contact 266 vdisengagesedge B of segment 221, which breaks the circuit through :the timing motor, and contact 266 has made contact with edge I) of segment 221. Also, contacts 261 and -266 have cleared edge B 01' segment 226, con- 1 tact; 2 and 242 are no longer in contact with 2,122,824 Jmoving from contact point266 at edge C. At this segment 26! and contacts 266 and 246 have not yet engaged the edge 13 of segment 226.

At the end of the rinsing operation, the eflluent water from the softener changes gradually from hard to soft. This is accompanied by alternate rising and falling of lather. In order to delay return to softening until a smooth and continuous lather appears in the trough, the edge B of segment! and edges B and D of segment 221 have a short circumferential gap between them. Thus, during the change the fluttering of. relay switch 266 causes contacts 266 and 266 to be closed intermittently, permitting the timing mothrough wire 266, wire 211, brush 226, arm 2",

segment '222, wire 262, contacts 266 and 246, segment 226, wire 264, wire 261, solenoid switch 2l6, wire 266 and wire 264. The valve motor is thus caused to turn the valve until arm 2" slides off segment 222 and on to segment 2". This breaks the switch for the valve motor and the motor stops, leaving the parts in the position indicated in Fig.v 11, The timing circuit is now closed through wire 264, points 266 and 266, wire 210, point 266, segment 221, point 216, wire 216, motor 226 and wire 266. The-timing motor runs until segment 221 breaks contact with point p 266 at edge C, as described. I I

The hardness tester can also be applied to any other softener of the automatic type adapted to initiate regenerationby opening or closing of an electric relay switch, the hardness tester serving in lieu or manualorwater meter actuation.

The elements of the hardness tester which come into contact with water or soap solution are advantageously made of bronze or stainless steel.

. What I claim is:-

1. Apparatus for producing an electrical indication dependent upon hardness in water, comprising a source of light, a photoelectric cell opposed thereto and receiving a beam of light therefrom; means for mixing water with soap solution in predetermined proportions and for agitating themixture, a container in conununication with said mixing means and adapted to contain a flowing stream of said soap and water mixture, said container being so located with respect to the source of lightand the cell and having walls so arranged that when the mixture forms a voluminous lather due to soft water the lather in the container diverts the light beam from the cell and thus causes a low degree of i1- iumination on the cell, and when the mixture forms no lather it flows along between the walls of the container without diverting saidlight beam and thus provides for a high degree oi illumination on the cell, and an electrical instrument in circuit with the cell and adapted to re spend to changes in illumination thereon and thus to hardness changes.

2. Apparatus for producing an electrical indication dependent upon hardnessin water, comprising a source of light, a photoelectric cell opposed thereto, a container adapted to hold a body of lather and having sides depressed below the line between the source and the cell so as not to obstruct illumination onthe cell, means for mixing water with soapsolution in predetermined proportions, means for agitating such mixture to the mixing chamber, means for controlling the and means for delivering the mixture to the container so that any lather formed extends above the depressed sides of the container and when no lather is formed the mixture does not extend above said depressed sides, and an electrical instrument in circuit with ,the photoelectric cell and adapted to respond to changes in illumination thereon and thus to respond to hardness changes.

3. Apparatus for producing an electrical indication oi hardness in water, comprising a source of light, a photoelectric cell opposed thereto, and an electrical indicating meter electrlcally connected to the cell, a containenbetween the source of light and the cell, the container having depressed portions lying below the line between the source and the cell so as not to obstruct illumination on the cell, means for mixing water with soap solution in predetermined proportions, means for agitating such mixture and feeding it to the container to form a lather of large volume extending above the depressions oi the container when the water is soft andto iorm curds of less volume not extending above such depressionswlren the water is hard, so that variations in hardness of the water are reflected as variations in illuminati'on on the cell.-

4. Apparatus for producing a power. impulse dependent upon hardness in water, comprising a source of light, a photoelectriccell opposed thereto, a container therebetween having sides which are depressed below the line between the source and the cell so as to expose the cell to the source, means for mixing water with soap solutionin predetermined proportions, means for agitating such mixture to form alather of large volume extending above the sides of the container when the water is soft and a curd of less volume not extending above the sides when the water is hard, so that illumination on the cell is varied with hardness of water, and an electrical relay in circuit with and operable by the cell and adapted to respond to variationsin cell current.

5. Apparatus for producing an electrical indication dependent upon hardness in water, comprising a source or light, a photoelectric cell opposed thereto, a container therebetween adapted to hold a body of lather and having sides which are depressed below the line between the source and the cell so as to expose the cell to the source, means for mixing water with soap solution in predetermined proportions, said means comprising a motor, a reciprocating pump for water driven thereby, a reciprocating pump for soap solution also driven by the motor, said pumps being adapted to perform suction and discharge strokes, conduit means connecting the water pump with a source of water to be tested and conduit means for admitting soap solution to the soap pump, joint conduit means delivering from the two pumps, valve means for alternately connecting the source 01' water and soap solution to the pumps at the beginning of the suction stroke and connecting the pumps with the joint outlet conduit at the beginning of the discharge stroke, means for .delivering the mixture otsoap and water to the container in the form oi a bulky lather or a curdy liquid depending upon the hardness of the water and an electricalindicating instrument in circuit with the photoelectric cell.

6. A hardness testing apparatus comprising a mixing chamber, a water supply pipe delivering rate of flow of water delivered to the mixing chamber, means for supplying soap solution to" the mixing chamber and for controlling the rate at which the soap solution is supplied, means for introducing air bubbles in the liquid contents of the mixing chamber, trough means providing an overflow for the mixing chamber, a source of light, means for projecting a beam of light from said source towards the mixture at a level above said overflow, a light sensitive cell in the path of said beam, the cell, source of light and trough means being so arranged that upon occurrence of lather the light beam'is diffused andlessened in intensity before it reaches the cell, and measuring means electrically connected to the light sensitive cell. a

7. Apparatus for producing an electrical impulse dependent upon hardness in water, 'comprising asource of light, a photoelectric cell opposed thereto and receiving a beam of light therefrom, means for mixing water with soap solution in predetermined proportions and for agitating the mixture,'a container in communication with said mixing means and adapted to contain a flowing stream of said soap and water mixture, said container being so located with respect to the source of light andthe cell and having walls so arranged that when the mixture forms a voluminous lather dueto soft water the lather in the container diverts the light beam from the cell and thus causes a low. 'degree of illumination on the cell, and when the mixture forms no lather it flows along between the walls of the container without diverting said light beam and thus provides for a high degree of illumination on the cell, an electrically operable relay switch in'circuit ,with the cell and adapted for actuation by the cell, an electric motor, multiple contact switching means driven by the motor, and appropriate electric power circuits for the motor, the relay switch and the switchingmeans, the relay switch being connected into the circuits in such manner that 'upon appearance of hardness the switch moves to close a circuit through the motor.

8. An optical method of testing water for hard ness which comprises mixing a stream of water to be tested and. a stream of soap solution with air,

flowing said aerated mixture as a stream, directing a beam of light across and above said stream a in such relation with respect to said stream that the beam is undiflused when the aerated mixture 4 is free of lather, while when the aerated mixture forms a lather due to soft water the beam is dit-r fused by said lather and lessened in intensity,

and measuring the intensity of said beam photoelectrically.

9. Hardness testing apparatus comprising a photoelectric cell, a receptacle, means for supplying water thereto, means for mixing soap' with the water in predetermined proportions to produce a lather when the water is soft, the receptacle being arranged to permit the lather to collect in a predetermined position. and a source 

